CN-121635088-B - Cutter shaft vector optimization method for wear homogenization

CN121635088BCN 121635088 BCN121635088 BCN 121635088BCN-121635088-B

Abstract

The invention discloses a cutter shaft vector optimization method for wear homogenization, which belongs to the technical field of numerical control machining tools and comprises the steps of inputting workpiece, cutter and machining path information, initializing a cutter shaft vector model, defining a cutter-workpiece meshing area, calculating and judging the cutting situation of a cutting edge, calculating the increment of the side face wear volume of a current time step and the cutting micro-element side face wear width of a next time step for the cutting edge section participating in cutting by using a wear mechanism analysis model, superposing the calculated cutter face wear width, iteratively adjusting the cutter shaft vector to realize uniform distribution of wear on the cutting edge, optimizing cutting parameters in a cooperative mode to control surface roughness, and outputting a wear homogenization machining scheme. By adopting the method, the active homogenization of cutter abrasion and the stable control of surface roughness are realized by dynamically optimizing the cutter shaft vector and cooperatively adjusting the cutting parameters, so that the service life of the cutter is obviously prolonged and the processing quality is ensured.

Inventors

SHEN BIN
WANG CHENGHAN
YUE TING
Tu Weiyi
NIE PENGFEI
CHEN SULIN

Assignees

上海交通大学

Dates

Publication Date: 20260505
Application Date: 20260204

Claims (5)

1. The cutter shaft vector optimization method for wear homogenization is characterized by comprising the following steps of: s1, defining initial parameters of a machining system, inputting workpiece, cutter and machining path information, and initializing a cutter shaft vector model; S2, defining and calculating a cutter-workpiece engagement area, judging the engagement state of the cutting element by adopting an improved empty ball judgment algorithm, and judging that the cutting edge participates in the cutting condition, wherein the specific contents are as follows: to establish a wear leveling basis, a tool-workpiece engagement area is defined as A set of points representing an engagement zone, the tool-workpiece engagement zone being an arbor vector Is calculated by geometrical intersection: ; Wherein, the Representing three-dimensional coordinate points; Representing a three-dimensional real set; The method comprises the steps of taking a cutting element as a center, constructing two characteristic spheres in combination with adjacent meshing points, wherein the radius of each sphere is R, the sphere center is coplanar with the cutting element and the meshing points, four points form a diamond topological structure on a normal vector plane, judging that the sphere is empty when no other meshing points exist in the sphere, traversing all meshing points in the radius of 2R to generate spheres, and judging that the current cutting element is separated from the meshing area and does not participate in cutting if any empty sphere exists; S3, for the cutting edge sections involved in cutting, calculating average normal stress and temperature acting on each cutting element side according to cutting parameters and current wear states, calculating the increment of the side wear volume of the current time step and the cutting element side wear width of the next time step by using a wear mechanism analysis model, and superposing and calculating the rear cutter face wear width, wherein the specific contents are as follows: For cutting edge sections involved in cutting, according to cutting parameters and current wear state The average normal stress and temperature acting on each of the cutting infinitesimal flanks were determined, and using a wear mechanism analysis model, the increase in flank wear volume was calculated from the thermo-mechanical load experienced in the current time step, the wear volume increase being expressed as follows: ; Wherein, the Is the cutting distance of the cutting primordia in the current step; And Is the wear rate coefficient calibrated through experiments; Representing the cutting temperature; representing contact normal stress; if the cutting element side surface is always flat, the abrasion width is increased And wear volume increment The relationship between them is defined as follows: ; Wherein, the And Representing a rake angle and a relief angle, respectively; The width of the wear of the side face of the cutting element in the next time step is calculated by the following formula: ; Finally, the abrasion of the cutting element along with the time is obtained, and the abrasion width of the rear cutter surface is obtained through superposition calculation; s4, realizing uniform distribution of abrasion on the cutting edge by iteratively adjusting the cutter shaft vector; S5, cooperatively optimizing cutting parameters to control surface roughness and compensate the influence of cutter shaft variation; and S6, outputting a wear homogenization processing scheme.
2. The method for optimizing the arbor vector for wear leveling according to claim 1, wherein S1 specifically comprises: defining initial parameters of a processing system, including a workpiece geometry model Wherein Representing coordinates of surface points of a workpiece, tool model Indicating that the tool is in the arbor vector Tool body and cutting edge model in state, and initial machining path Wherein Is a path parameter; At the same time, initializing the cutter shaft vector Is a unit vector, which represents the initial cutter shaft direction and initializes the wear distribution function Wherein As a point on the cutting edge, Time, and set initial wear to zero: 。
3. The arbor vector optimization method for wear leveling according to claim 1, wherein S4 is as follows: Defining an objective function As a wear non-uniformity measure, the expression is: ; Wherein, the Representing the cutting edge area; In each iteration, extracting the current cutter shaft vector Lower tool-workpiece engagement area Then judging the cutting edge to participate in the cutting condition, and according to the abrasion calculation model, superposing and calculating the abrasion width of the rear cutter surface so as to infer the cutter shaft vector The abrasion non-uniformity is iterated by a gradient descent method based on the cutter shaft vector Up to the value of the gradient of the objective function Converging to a threshold value And (5) the maximum iteration times are reached, so that the uniform wear distribution of the cutter shaft vector after optimization is ensured.
4. A wear leveling-oriented arbor vector optimization method according to claim 3, wherein S5 is as follows: After the cutter shaft vector is optimized, the surface roughness is maintained stable by adjusting the cutting parameters, firstly, the surface roughness is established Inclination angle corresponding to cutter shaft vector Relation of cutting parameters; Surface roughness Typically per tooth feed And cutting speed The empirical model is related: ; Wherein: is a constant related to the tool and the material; Is the feed per tooth of the sheet, , The number of teeth of the cutter; Is the cutting speed of the tool, Is a positive constant; Cutting speed at cutting point Subject knife axis vector Normal to the surface Corresponding inclination angle of (2) The specific relationship is as follows: ; Wherein, the Is the diameter of the cutter, Is the spindle speed; Will be And Substitution into Model, simplified to: ; Wherein, the Is a constant; to keep the surface roughness uniform, make The temperature of the liquid is constant and the liquid, The method comprises the following steps of: ; The method comprises the following steps: ; corresponding inclination angles for different cutter shaft vectors Adjustment of And So that it satisfies the above-mentioned formula, Representing the feed speed; Indicating spindle speed.
5. A wear leveling-oriented arbor vector optimization method according to claim 3, wherein S6 is as follows: the output comprises an optimized cutter shaft vector sequence Corresponding feed speed And spindle speed And predicted wear distribution Wherein in the sequence of arbor vectors For the number of the path points, the method also comprises surface roughness verification data, so that The values are within allowable tolerances.

Description

Cutter shaft vector optimization method for wear homogenization Technical Field The invention relates to the technical field of numerical control machine tools, in particular to a cutter shaft vector optimization method for wear homogenization. Background In the high-end manufacturing field, the service life and the processing surface quality of the cutter are core indexes for measuring the technological level, and are directly related to the production takt, the finished product rate of parts and the service performance of the final product. Particularly in the five-axis machining of complex freeform surface parts such as a die, an aeroengine blade and the like, the production cycle of a single piece is long, the cost of the cutter is high, the premature failure of the cutter not only causes the shutdown loss of interrupting machining and replacing the cutter, but also can discard high-value workpieces due to the out-of-tolerance size or surface defects. Therefore, the realization of effective control and prediction of tool wear, while guaranteeing stable surface integrity, is a key challenge in achieving efficient, reliable, economical machining. The current technical solutions mainly focus on the following directions of cutting parameter optimization, namely adjusting feeding and rotating speed under a fixed cutter shaft, wherein the method is simple, but has limited optimizing potential, and cannot radically treat local abrasion, geometric-based cutter shaft planning, namely aiming at realizing collision-free machining or controlling cutter marks, changing the cutter shaft but not designed for homogenizing abrasion, wherein the sporadic abrasion dispersion effect is uncontrollable and possibly sacrificing surface quality, and periodic cutter shaft swinging, namely, as a preliminary attempt, the swinging mode of the periodic cutter shaft is lack of association with specific meshing state and roughness, belongs to open-loop empirical control, and is easy to cause unstable cutting or deterioration of surface quality. None of the above methods systematically synergistically optimizes the two objectives of "active wear leveling" and "surface quality closed loop control". The fundamental bottleneck is that an integrated model capable of accurately describing the internal relation among the cutter shaft vector, the dynamic meshing area and the final surface roughness is missing, so that the intelligent process planning of the cutter shaft vector, the dynamic meshing area and the final surface roughness cannot be realized. Disclosure of Invention The invention aims to provide a cutter shaft vector optimization method for wear homogenization, which aims to solve the problems in the background technology. In order to achieve the above purpose, the invention provides a cutter shaft vector optimization method for wear homogenization, which comprises the following steps: s1, defining initial parameters of a machining system, inputting workpiece, cutter and machining path information, and initializing a cutter shaft vector model; s2, defining and calculating a cutter-workpiece engagement area, and judging the engagement state of the cutting element by adopting an improved empty ball judgment algorithm to judge the cutting situation of the cutting edge; S3, for the cutting edge sections involved in cutting, calculating average normal stress and temperature acting on each cutting element side according to cutting parameters and current wear states, calculating the increment of the side wear volume of the current time step and the cutting element side wear width of the next time step by using a wear mechanism analysis model, and superposing and calculating the rear cutter face wear width; s4, realizing uniform distribution of abrasion on the cutting edge by iteratively adjusting the cutter shaft vector; S5, cooperatively optimizing cutting parameters to control surface roughness and compensate the influence of cutter shaft variation; and S6, outputting a wear homogenization processing scheme. Preferably, S1 specifically includes: defining initial parameters of a processing system, including a workpiece geometry model WhereinRepresenting coordinates of surface points of a workpiece, tool modelIndicating that the tool is in the arbor vectorTool body and cutting edge model in state, and initial machining pathWhereinIs a path parameter; At the same time, initializing the cutter shaft vector The initial arbor direction is represented as a unit vector, typically based on conventional tooling strategy settings. Initializing wear distribution functionsWhereinAs a point on the cutting edge,Time, and set initial wear to zero: 。 The above input parameters provide the basic data for the subsequent iterative optimization. Preferably, the specific content of S2 is as follows: To establish a wear leveling basis, a tool-workpiece engagement area (Cutter-Workpiece Engagement, CWE) is defined as A set of points representing an engagement